Subdivision Surface Artifact with Creases
Your geometry is not exactly flat. If you look at it from the top, you will see this.

I suggest moving your vertices like this:



But your main problem is that the creases end inside the mesh. If you extend them all the way to the end of your mesh, it will be without artifacts. Like this.



You can also clear the crease and insert two edge loops. I find it slightly easier to control the exact bevel this way. Use ctrl + R to create a edge loop. Click on the faces where you want it. Slide it up where you want it. Left click to finish placement.